This year he is among six veteran teachers who could lose their jobs because they lack the proper teaching credentials to serve students with limited English skills.

The six are on a list to be suspended without pay, pending termination. The Hillsborough County School Board will vote on these actions at its next meeting Tuesday.

Half, including Leonard, teach students with disabilities.

Because of Florida's large population of students who are not proficient in English, teachers often are required to get training in English for Speakers of Other Languages, known as ESOL. The requirement is intended to protect students who are assigned to their classes despite language barriers.

The teachers in question did not obtain their ESOL qualifications, called endorsements, according to letters from the district.

The documents cite a legal agreement with LULAC, the League of United Latin American Citizens, which sued the state over this issue in 1990.

Leonard could not be reached for comment Wednesday, nor could the other five.

A school district employee since 2002, Leonard teaches emotionally and behaviorally disturbed students at Progress Village Middle Magnet School. In his contest essay in 2013, he described his work as a mentor, classroom teacher and tutor who follows his students through high school to make sure they remain focused on their studies.

Two of the others — Lea Lewis at Benito Middle School and Carl Canion at Jefferson High — also teach disabled students.

The remaining three — Beverly Baker at Barrington Middle, Teresa Klag at Marshall Middle and Mitchell Rebenstorf at Wharton High — teach English and reading.

It was not clear Wednesday from district officials whether this move was unusual, or if the teachers might be given another chance to update their credentials to avoid being fired.

"We wouldn't be at this stage if they didn't already have multiple opportunities," said district spokesman Stephen Hegarty.

Stephanie Baxter-Jenkins, executive director of Hillsborough's teachers union, said she has already contacted the district with concerns about what she characterized as harsh language in the letters. She also believes some may have been written in error.

For instance, the Wharton teacher was in the process of completing his requirement, she said.